Microwave communication uses high-frequency (1)______ waves that travel in straightlines throughthe air. Because the waves cann

admin2013-01-05  47

问题 Microwave communication uses high-frequency  (1)______ waves that travel in straightlines throughthe air. Because the waves cannot  (2)______with the curvature of the earth, they can be  (3)_____only over short distance. Thus, microwave is a good  (4) ______for sendingdata between buildings ina city or on a large college campus. For longer distances, the wavesmust be relayed by means of"dishes" or  (5)_____. These can be installed on towers, highbuildings, and mountain tops.
(3)______
A.transmitted
B.transformed
C.converted
D.Delivered

选项 A、 
B、 
C、 
D、 

答案A

解析
转载请注明原文地址:https://kaotiyun.com/show/lWkZ777K
0

相关试题推荐
最新回复(0)